There is provided a method for controlling driving of an inkjet head including recording elements each including a nozzle and a driving element. The method includes a pulse width setting step. In this step, when a predetermined number of ink droplets ejected according to the predetermined number of driving pulses are made to land in the same pixel range, the predetermined number of first driving pulses each having a pulse width longer than a reference pulse width and the predetermined number of second driving pulses each having a pulse width shorter than the reference pulse width are combined for each of the recording elements and obtained combinations are respectively output to the recording elements. The predetermined number is two or more.

A method for depositing droplets onto a medium, utilising a droplet deposition head is provided. The head used in the method includes: an array of fluid chambers separated by interspersed walls, each fluid chamber communicating with an aperture for the release of fluid droplets and each wall separating two neighbouring chambers. Each wall is actuable such that in response to a first voltage, it will deform so as to decrease the volume of one chamber and increase the volume of the other chamber, and, in response to a second voltage, it will deform so as to cause the opposite effect on the volumes of its neighbouring chambers. The method includes the steps of: receiving input data: assigning, based on such input data, all the chambers within the array as either filing chambers or non-firing chambers, so as to produce bands of one or more contiguous filing chambers separated by bands of one or more contiguous non-firing chambers; actuating the walls of certain of the chambers such that: for each non-firing chamber, either one wall is stationary while the other is moved, or the walls move with the same sense, or they remain stationary: and, for each firing chamber the walls move with opposing senses; such actuations result in each firing chamber releasing at least one droplet, the resulting droplets forming bodies of fluid disposed on a line on the medium, such bodies of fluid being separated on the line by respective gaps for each of the bands of non-firing chambers, the size of each such gap generally corresponding in size to the respective band of non-firing chambers. The actuations of the walls of said firing chambers in the actuating step are such that, if only one of the two walls of each firing chamber were actuated in such manner, no droplets would be ejected from that firing chamber. A droplet deposition apparatus, a droplet deposition head and a computer program product are also provided.

Provided is a liquid droplet generation method capable of generating liquid droplets having a diameter of 100 .Math.m or more. The liquid droplet generation method for generating liquid droplets from a liquid layer 20 by using a plurality of transducers 18, the method including irradiating the liquid layer 20 with a plurality of ultrasonic waves from the plurality of transducers 18 to scatter primary liquid droplets 21A and 21B from the liquid layer 20, and causing the primary liquid droplets 21A and 21B being scattered to aggregate and grow into a secondary liquid droplet 22A.

A liquid discharge apparatus includes a liquid discharge head configured to discharge a liquid, and a drive waveform generator configured to generate a drive waveform to be applied to the liquid discharge head, the drive waveform including a first discharge pulse to cause the liquid discharge head to discharge the liquid, a second discharge pulse after the first discharge pulse, the second discharge pulse to cause the liquid discharge head to discharge the liquid, and a pulse interval between the first discharge pulse and the second discharge pulse, the pulse interval being equal to a time period in which the liquid is discharged by the second discharge pulse in a damping state in which the second discharge pulse is damped by a meniscus vibration generated by the first discharge pulse.

A method of driving an inkjet head having a nozzle and a pressure generator, a plurality of droplets of the ink discharged in response to a series of the drive signals being caused to hit a recording medium to form a single pixel. The method includes, applying, to the pressure generator, the series of the drive signals including a first one of the drive signals that has a first voltage amplitude and a second one of the drive signals that has a second voltage amplitude larger than the first voltage amplitude. A last drive signal in the series of the drive signals is the second one of the drive signals. The first voltage amplitude and the second voltage amplitude are determined such that a ratio of (first voltage amplitude)/(second voltage amplitude) has a value corresponding to a specific gravity of the ink to be discharged.

There is provided an ink jet recording apparatus including an ink jet head and a drive circuit. The ink jet head forms an image on a recording medium in response to a drive signal applied to multiple piezoelectric elements. The drive signal causes multiple pressure chambers corresponding to the multiple piezoelectric elements to expand or to contract in volume and causes ink in the multiple pressure chambers to be discharged from multiple nozzles. The drive circuit generates a drive signal for discharging multiple liquid droplets to one pixel for combining the multiple liquid droplets together and applies the drive signal to each of the multiple piezoelectric elements of the ink jet head. The drive signal includes multiple discharge pulses which make velocities of tips of respective liquid columns substantially same after a predetermined time from starting of ink discharge from the nozzles.

A liquid ejecting apparatus includes ejecting sections that eject droplets from nozzles according with a driving signal supplied thereto. The driving signal includes a plurality of ejection pulses during one cycle. The plurality of ejection pulses includes a final ejection pulse corresponding to a final droplet. The final ejection pulse includes an expansion element that expands a pressure chamber, an expansion-maintaining element that maintains the expansion of the pressure chamber, a contraction element that contracts the pressure chamber, and a vibration-damping element that reduces residual vibration of liquid in the pressure chamber. The time width of the sum of the expansion element and the expansion-maintaining element of the final ejection pulse is longer than a length that is 0.5 multiplied by the natural-vibration cycle of the ejecting sections, and is shorter than a length that is 1.0 multiplied by the natural-vibration cycle.

There is provided an ink jet recording apparatus including an ink jet head and a drive circuit. The ink jet head forms an image on a recording medium in response to a drive signal applied to multiple piezoelectric elements. The drive signal causes multiple pressure chambers corresponding to the multiple piezoelectric elements to expand or to contract in volume and causes ink in the multiple pressure chambers to be discharged from multiple nozzles. The drive circuit generates a drive signal for discharging multiple liquid droplets to one pixel for combining the multiple liquid droplets together and applies the drive signal to each of the multiple piezoelectric elements of the ink jet head. The drive signal includes multiple discharge pulses which make velocities of tips of respective liquid columns substantially same after a predetermined time from starting of ink discharge from the nozzles.

The present invention has a problem of suppressing liquid gathering of an interpolation dot which interpolates a discharge defective nozzle and preventing deterioration of image quality, and the problem is solved by the present invention including: an inkjet head configured to separately discharge a large droplet, a medium droplet, and a small droplet from each of a plurality of nozzles; and a control unit which forms an image in a single-pass system by discharging the medium droplets from the plurality of nozzles respectively, and forms an interpolation dot to interpolate a discharge defective nozzle by discharging a droplet from a different nozzle when the discharge defective nozzle is present, the control unit forming the interpolation dot to interpolate the discharge defective nozzle with the use of the large droplet and forming at least one adjacent dot which is in contact with the interpolation dot with the use of the small droplet.

A method for depositing droplets onto a medium, utilising a droplet deposition head is provided. The head used in the method includes: an array of fluid chambers separated by interspersed walls, each fluid chamber communicating with an aperture for the release of fluid droplets and each wall separating two neighbouring chambers. Each wall is actuable such that in response to a first voltage, it will deform so as to decrease the volume of one chamber and increase the volume of the other chamber, and, in response to a second voltage, it will deform so as to cause the opposite effect on the volumes of its neighbouring chambers. The method includes the steps of: receiving input data: assigning, based on such input data, all the chambers within the array as either filing chambers or non-firing chambers, so as to produce bands of one or more contiguous filing chambers separated by bands of one or more contiguous non-firing chambers; actuating the walls of certain of the chambers such that: for each non-firing chamber, either one wall is stationary while the other is moved, or the walls move with the same sense, or they remain stationary: and, for each firing chamber the walls move with opposing senses; such actuations result in each firing chamber releasing at least one droplet, the resulting droplets forming bodies of fluid disposed on a line on the medium, such bodies of fluid being separated on the line by respective gaps for each of the bands of non-firing chambers, the size of each such gap generally corresponding in size to the respective band of non-firing chambers. The actuations of the walls of said firing chambers in the actuating step are such that, if only one of the two walls of each firing chamber were actuated in such manner, no droplets would be ejected from that firing chamber. A droplet deposition apparatus, a droplet deposition head and a computer program product are also provided.